Simply turning on a light at night for a few seconds to go to the toilet can cause
changes that might lead to cancer, scientists claim. Researchers in the UK and Israel
found that when a light is turned on at night, it triggers an 'over-expression' of
cells linked to the formation of cancer.Previous research has linked an increased risk
of breast cancer and prostate cancer in workers exposed to artificial light on night
shifts.
But researchers said the latest research is the first that shows even short-term
exposure can be linked to an increased risk of cancer. The tests were carried out on
mice at Leicester University by geneticist Professor Charalambos Kyriacou. During the
trial, a group of mice were exposed to a light for one hour. When compared with mice
who had been kept in the dark, changes were found in cells in the brain responsible
for the circadian clock which controls body function. Dr Rachel Ben-Shlomo, of the
University of Haifa, said in the journal Cancer Genetics and Cytogenetics that people
waking at night would be best advised not to turn on the light.